Green soybeans are soaked overnight, cooked only until they still have some resistance to the tooth, and cooled. Then they go into dashi seasoned with soy sauce, mirin, and salt, and sit there. That is the whole dish.

What you taste when you bite one is the sweetness of the bean and almost nothing else.

The Nishiyama district in the north of Nagano has soil that suits soybeans, and wheat and pulses have been grown there for a very long time, on ground that would not carry much else. The beans from that area are good enough to have a name of their own: Nishiyama daizu.

It is also made with kurakake beans, a green soybean whose markings look like a saddle laid across a horse's back, which is where the name comes from, and which are said to have something of the flavor of nori about them. The dish belongs to northern and eastern Nagano, and it is eaten in Niigata and across the northeast as well. It sits on the table as an everyday side dish and comes out with tea in the afternoon. At new year it goes into the osechi boxes, and mixed with herring roe it becomes kazunoko-mame, which is a different dish under a different name made of the same beans.